The present technology relates to a biaxially oriented polypropylene film.
Biaxially oriented polypropylene films, also known as oriented polypropylene films, are used in a wide range of technical applications such as packaging, tapes or capacitor films. Desired properties of these films are high stiffness and good thermal resistance. At the same time, the film should have beneficial processing properties. In particular, it is of interest to have a low drawing temperature while still obtaining films with high draw ratios and no film breaking or sagging. However, any improvement in processability should not be achieved at the expense of mechanical and/or thermal properties of the final film.
EP 0745637 A1 discloses a biaxially oriented polypropylene film having a high surface modulus and a n-heptane soluble fraction of less than 1 wt %. A single site metallocene catalyst is used for the preparation of the polymer.
WO 98/10016 discloses a biaxially oriented film made from a polypropylene which comprises a homopolymer fraction and a copolymer fraction. In the process for the preparation of the polypropylene, two different metallocene catalysts are used.